The Darkest Skies
in Washington

"Instrument set up on ridge just NW of the lookout. Seeing good, transparency very good. Glow to the northwest from airglow or aurora, not as bright east or southeast. Small light dome due north, fainter than Jupiter, another fainter smaller light dome northeast. Toward Columbia Falls lots of light, bright white glare illuminating the mountains from some sort of industrial yard, at least 10 unshielded lights visible, bright enough to kill night vision, casts shadows. Wonderful sky if you can get away from the glare. Milky Way directly overhead, very bright with much detail in Cygnus, all the rifts and holes apparent, North America nebula an easy visual object. Also in Cassiopeia much detail, bridge in the MIlky Way north of Mirfak visible. Sagittarius Milky Way washed out by Columbia falls area, the light dome of which extends 30 degrees from horizon upward, 40-50 degrees wide."

"Very clear night! Cloud free, but fire smoke visible to the south and east from N. Calofornia fires. Possibly some smoke to the north low along the horizon. No visible light domes in any direction and only one or two single glare sources in the valleys below from ranches. Exceptionally bright Milky Way with rich detail from Sagitarrius Star Cloud to Cygnus. Easily visble from horizon to horizon. M31 easily visble with naked eye. SQM readings probably a little low due to Milky Way being almost overhead. Milky Way casting shadows with no problem. One of the best nights skies this observer has seen."

"Some smoke on horizon, but no noticable light domes or any light pollution. Slight brightening to NW. Began the evening with some clouds to the south and east which receeded. Smoke layer along horizon to south/SW and some to the north. Clear overhead. Slightly hazier than last night. Airglow may be prison to the northwest and southeast. Milky Way is easily seen with wonderful detail spans from southwest horizon below Sagitarrius overhead to northeast well beyond Cassiopia through Persius to horizon. Great rift is well defined, prancing horse is visible. Star clouds are bright! Milky Way is 23 degrees wide at Sagitarrius."

"Walk to the pass between the Hidden Lakes Peaks on the Lookout trail. The higher summit is to the north (7080’), the south summit contains the old fire lookout building. The north summit is the best monitoring site, but difficult to access from the south because of large blocky boulders. Ascended a snowfield to a low point in the ridge at 6850’, at the base of the slope leading to the northern summit. Very good monitoring site with plenty of room to set up and safe location for people. Night of Perseid meteor shower, many bright meteors seen. Bortle Class 3. Seeing very good, transparency fair. Smoke from distant fires throughout, brown color seen to east. Visiblility in daytime no more than 40 miles. Light dome seen from Vancouver as a broad glow stretching from 340 azimuth across the northwestern horizon, centered on Mt. Baker, to about 300, up to 15 degrees altitude, significantly brighter than the brightest part of the Milky Way. Another light “bump” at 270-280, much smaller than Vancouver, then an even brighter light dome beginning at 220, 35-40 degrees wide, 15-20 degrees tall, bright enough to affect night vision. No other light domes. Bright airglow, extending to 30-35 degrees altitude. Around the Zenith, the Milky Way exhibits all details from Scutum to Cassiopeia, excellent sky within 40 degrees of Zenith. Zodiacal Light not seen, partly because of its position low in the east and south. Darkest area of the sky around the head of Draco, considerably darker than the other side of the Milky Way where more airglow is present. SQM 21.42 end of 4th set. ZLM 7.1 in Draco (both Dan and Bob)."

"Diablo Lake Overlook, set up at the overlook handrail. Beautiful sky, despite direct glare from unshielded lights on Diablo Dam. These are bright enough to affect night vision, but amber in color. Near the Zenith the sky is pristine, and this location would make an excellent place for public astronomy programs, just need to strategically put trees to shield dam lights and the headlights from cars on the highway. Illuminance measures taken with ND filter of the dam lights. Two full sets of night sky data taken despite horizon obstructions from mountain peaks. Difficult to rate as to Bortle class because of the obstructions, but nearly Class 2; traces of a light dome to the west seen at low points in the horizon. Airglow bright again, ZLM 7.1. Transparency good, seeing good."

"Set up camera equipment on the trail to the camp. Clouds in the afternoon all cleared out by 9:00 pm, though it appeared as if some fire smoke moved through the northern horizon later in the night. Excellent night sky viewing from this park, rivaling sites on the Colorado Plateau. A single yard light on a ranch building 2.5 miles north was bothersome, otherwise no visible lights seen from this location. A very faint light dome from Butte (60 miles distant) and nothing apparent from Wisdom, the nearest community (9 miles). Very fine detail visble in the Milky Way, with the Prancing Horse easily seen and the dust lanes in great detail. Stars are visible to the horizon in the south. Saw limiting magnitude star of 7.2 in Draco. Mars and Jupiter very bright to the SE and SW."

"Transparency remarkably good after yesterday's fire smoke, seeing very good. Few high clouds to the west and north, remnants of fire smoke to the northeast. Direct glare from many very bright lights on Vancouver Island and a few Port Angeles lights, otherwise the high ridges of the Olympic Mountains effectively block any other glare from the Puget Sound area. After moon sets, the zenith is quite dark with the Cygnus Milky Way very detailed, but a broad and fairly bright light dome toward Seattle and Puget Sound dominates the eastern sky. Excellent site for monitoring. Perhaps an area 30 degrees in diameter near the zenith offers reasonable visual observations. Otherwise the sky is very modified by light pollution. ZLM 6.9 with difficulty, the eastern sky must be shielded by the ridgetop to achieve this as it definitely affects scotopic vision. The treeless ridge is easy to navigate by the light of the sky. Milky Way easily seen near the zenith,but loses its character rapidly approaching the horizon. Fog appears to move in in early morning through the Strait of Juan de Fuca into the northern Puget Sound area, suppressing light pollution and significantly improving the sky quality."

"Sky quality measurements were recorded at Burroughs Mountain in Mount Rainier NP on 8/13/2007. The site demonstrated a scientific darkness reading of 21.28 SQM."

"Considerable detail visible in Milky Way, including dust lanes of Cygnus. M31 an easy averted, but difficult direct vision object. Faint shadows are cast by the light of Seattle/Tacoma. High humidity visible in valley below (settling into a very thin fog). Coastal cloud wall evident to west. ZLM of 6.4 seen in Auriga. SQM: 21.12 (1st), 21.08 (2nd), 21.17 (3rd)."

"Partly cloudy at the beginning of the night and gradually became clear later. Humid but no wind."